Nanocrystalline formation in amorphous Fe_(79)B_(16)Si_5 and Fe_(78)B_(13)Si_9 ribbons

摘要

Nanocrystalline formation in the amorphous ribbons, Fe_(79)B_(16)Si_5 and Fe_(78)B_(13)Si_9, resulting from annealing the ribbons at temperatures below their crystalline temperature is followed by Mossbauer spectroscopy. It is seen that in the B-rich Fe_(78)B_(16)Si_5 ribbons, the crystallization is a two stage process: amorphous -> #alpha#-Fe(Si) nanocrystalline formation -> (#alpha#-Fe, Fe_2B) nanocrystalline formation while the crystallization in the B-poor Fe_(78)B_(13)Si_9 ribbons is a three stage process: amorphous -> Fe_3B nanocrystalline formation -> #alpha#-Fe(Si) nanocrystalline formation -> (#alpha#-Fe, Fe_2B) nanocrystalline formation. These direct observation confirms the inferred formation of nanocrystallites obtained from magnetization measurements of similar type Fe-si-B amorphous alloys. Our study also indicated that the #alpha#-Fe(Si) nanocrystallites survives at the higher temperatures.